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Governments in many countries restrict citizens' access to information and services on the Internet in one way or another. Combating such censorship is an important and difficult task. Usually simple solutions cannot boast about high reliability or long-term efficiency. More complex methods of overcoming blocks have disadvantages in terms of usability, low performance, or they do not allow you to maintain the quality of Internet use at the proper level.
A group of American scientists from the University of Illinois has developed a new method of overcoming blocks, which is based on the use of proxy technology, as well as segmenting users by trust level to effectively identify agents working for censors. We present you with the main theses of this work.
Description of the approach
Scientists have developed the Salmon tool, a system of proxy servers operated by volunteers from countries without restrictions on Internet use. In order to protect these servers from blocking by censors, the system uses a special algorithm for assigning a level of trust to users.
The method involves exposing potential censor agents that pose as ordinary users in order to find out the IP address of the proxy server and block it. In addition, countering Sybil attacks is carried out through the requirements to provide a link to a valid social network account when registering in the system or to receive a recommendation from a user with a high level of trust.
How it works
It is assumed that the censor is a state–controlled body that has the ability to take control of any router within the country. It is also assumed that the task of the censor is to block access to certain resources, and not to identify users for further arrests. The system cannot prevent such a course of events in any way – the state has plenty of opportunities to find out what services citizens use. One of them is the use of honeypot servers to intercept communications.
It is also assumed that the state has significant resources, including human ones. The censor can solve tasks that require hundreds and thousands of full-time employees.
A few more basic theses: